Mark Houlahan
Brand Manager, Mustang Monthly
February 1, 2004

Horse Sense:
Cylinder-head gaskets are not cheap (for the good ones, at least), and once the engine is back together they're not easy to replace. So, make sure you have the correct cylinder-head gasket or use the gasket recommended by the cylinder-head manufacturer. Ensure the block surface is prepared properly for a good gasket seal and that the gaskets are positioned correctly on the block.

If you're a regular reader of my automotive babbling, you're sure to remember the 5.0 Basics arti-cles in the August ("Air Apparent," p. 151) and September ("Getting Shafted," p. 153) '03 issues. We worked on Brian Wesche's '89 GT, enhancing its breathing capabilities via an Edelbrock intake and Crane cam. Now we plan to tie all the upgrades together via the installation of Edelbrock's Performer 5.0 cylinder heads.

For many of you, installing cylinder heads is a new adventure. That's why we're here to hold your hand. There are likely quite a few of our readers who can swap cylinder heads in two hours in the trailer, at the track, in the rain, and with no air tools-but that's not who this article is for. So, if you've thought about what it takes to crack open a 5.0 and do some serious work, we have the information you need.

Of course, in only four or five pages we can't show you every nut and bolt, so we always encourage the ownership and use of a good shop manual. Whether you acquire it from Ford or the aftermarket, a shop manual will help with some of the minor details and the ever-important torque specs. Just follow the directions, work methodically, and you shouldn't have any problems. Sure, the first time you yank a set of cylinder heads it might take you all weekend, but with experience comes efficiency, and you'll soon be helping your friends swap cylinder heads in half the time.

For Brian's GT, we chose Edelbrock Performer 5.0 cylinder heads for a simple bolt-on that would accept all the modifications that have already been added to his car. These heads accept stock valvetrain components, stock-bolt-pattern headers, and all Ford intake manifolds. To minimize clean-up time, we also ordered new head bolts, head-bolt washers, and intake bolts.

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On the Dyno
RPMBaselineCrane
PowerMax 2031
Edelbrock
Performer 5.0 Heads
TorquePowerTorquePowerTorquePower
3,200214.54131.40249.41152.35229.28144.74
3,300212.42133.97252.31157.85228.67146.81
3,400203.69131.83241.57155.71228.06148.88
3,500194.96129.68230.82153.71230.79154.13
3,600206.13141.58242.07165.76236.86162.57
3,700217.30153.48253.31177.94242.94171.00
3,800221.17160.29258.15186.31244.89177.10
3,900217.74162.01256.57190.85246.83183.19
4,000214.31163.73255.00195.39247.81188.60
4,100215.22167.97248.90194.63247.80193.31
4,200216.14172.21242.80193.86247.79198.02
4,300216.97176.92241.46197.43248.03202.91
4,400217.72182.09244.89205.32248.27207.81
4,500218.47187.26248.31213.20247.71212.03
4,600214.39188.11233.25203.99246.34215.59
4,700210.30188.97218.18194.78244.97219.14
4,800203.24186.37213.22194.46242.43221.35
4,900193.18180.31218.37203.05239.89223.56
5,000183.13174.26223.52211.63237.10225.39
5,100188.00182.18217.51210.32234.05226.83
5,200192.86190.11211.50209.01231.01228.28
5,300192.22192.91205.65207.47226.96228.71
5,400186.07190.60199.95205.70222.91229.13
5,500179.92188.29194.26203.92218.22228.58
5,600175.24185.74191.41204.03212.88227.05
5,700170.56183.20188.57204.14207.54225.51
5,800134.57145.54149.71163.36203.85223.32
5,900n/an/an/an/a200.16221.12
6,000n/an/an/an/a158.65176.02

When we began working on Brian's Mustang, it was already adorned with JBA Shorty headers, a Flowmaster exhaust, underdrive pulleys, and gears.The car was a blast to drive. Then we dropped an Edelbrock Performer 5.0 intake into the mix. These parts are all included in the baseline dyno testing. If you remember Brian's cam swap ("Getting Shafted," Sept. '03, p. 153), the GT made 213 hp and 258 lb-ft of torque on Lugo Performance's Mustang Dyno. After swapping the heads for Brian, we had him take his GT back to Lugo's for another spin on the rollers to see what the new heads did for the combination. The GT walked away with another 16 hp. Brian says the car is more fun to drive now, and that with the heads in place he can hear the cam in the exhaust more now, which he likes. With a larger throttle body (he's running a used 65mm), a mass air meter, and some tuning on the fuel system, we're sure Brian could see more horsepower out of this package.

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